OSTREA. 
spaces, and overspread with a diaphanous 
epidermis, resembling thus the armadillo 
among quadrupeds. It is a native of the 
American and Indian seas, is thought a high 
delicacy in India, and lives, it is supposed, 
on worms and shell fish. 
OSTREA, the oyster, in natural history, 
a genus of the Vermes Testacea class and 
order. Animal a tethys : shell bivalve, ge- 
nerally with unequal valves and slightly 
eared ; hinge witliout teeth, but furnished 
with an ovate hollow, and mostly lateral 
transverse grooves. About 150 species have 
been enumerated, and classed into sections 
and subsections. A. furnished with ears 
and radiate ; scallop. B. rough, and gene- 
rally plated on tlie outside ; oysters. C. 
hinge with a perpendicular grooved line. 
Most of this genus are furnished at the hinge 
internally with numerous parallel transverse 
grooves in each valve, and are immediately 
distinguished from the genus area, in not 
having teeth alternately locking in, each 
other. Scallops leap out of the water to the 
distance of half a yard, and opening the 
shells, eject the water within them ; after 
which they' sink under the water, and sud- 
denly close the shells with a loud snap. O. 
maxima : shell with about fourteen rounded 
and longitudinally striate rays ; is found in 
most European seas, in large beds, whence 
they are dredged up, and pickled and bar- 
relled for sale. This, we are told, is the 
shell which was formerly worn by pilgrims 
on the hat or coat, as a mark that tiiey had 
crossed the sea, for the purpose of paying 
their devotions at the Holy Land ; in com- 
memoration of which it is still preserved in 
the arms of many families. O. edulis : shell 
nearly orbicular and rugged, with undulate 
imbricate scales ; one valve flat and very 
entire. Of tliis species there are many va- 
rieties, They inhabit European and Indian 
seas, affixed to rocks, or in large beds ; the 
fish is well known as a palatable and nutri- 
cioHs food. The shell is of various sizes, 
forms, and colours ; within white, and often 
glossy like mother of pearl ; the old shells 
have often an anomia fixed to them, and are 
frequently covered with serpulae, lepades, 
Sertularia, and other marine productions. 
The following account has been given by 
Dr. Sprat of the treatment of oysters. 
In the month of May the oysters cast 
their spawn, (which the dredgers call their 
spats), it is like to a drop of a candle, and 
about the bigness of a halfpenny. The spat 
cleaves to stones, old oyster-shells, pieces of 
wood, and such like things, at the bottom of 
VOL. V. 
the sea, wliich they call erdteh. It is pro- 
bably conjectured, that the spat in twenty- 
four hours, begins to have a shell. In the 
month of May, the dredgers (by the law of 
the Admiralty Court) have liberty to catch 
all manner of oysters of what size soever. 
When they have taken them, with a knife 
they gently raise the small brood from the 
cultch, and then they throw ffie cultch in 
again, to preserve the ground for the future, 
unless they be so newly spat that they 
cannot be safely, severed from fhe cultch ; 
in that case they are permitted to take die 
stone, or shell, &c. that the spat is upon, 
one shell having many times twenty spats. 
After the month of May, it is a felony to 
carry away the cultch, and punishable to 
take any other oysters, unless it be those of 
size (that is to say) about the bigness of a 
half-crown piece, or when, the two shells 
being shut, a fair shilling will rattle be- 
tween them. Tlie places where the oysters 
are chiefly catched, are called the Pont 
Burnham, Malden, and Colne Waters ; the 
latter taking its name from the river of 
Colne, which passeth by Colne Chester, 
gives the name to that town, and runs into 
a creek of the sea at a place called the 
Hythe, being the suburbs of the towm. 
This brood and other oysters they carry to 
creeks of the sea, at Brickel Sea, Mersey, 
Langno, Fingrego, Wivenho, Tolesbury, 
and Saltcoase, and there throw them into 
the channel, which they call their beds or 
layers, where they grow and fatten, and in 
two or three years the smallest brood will 
be oysters of the size aforesaid. 
Those oysters which they would have 
green, they put into pits about three feet 
deep in the salt marshes, which are over- 
flowed only at spring tides, to which they 
have sluices, and let in the salt water until 
it is about a foot and a half deep. These 
pits, from some quality in the soil co-ope- 
rating with the heat of the sun, will become 
green, and communicate their colour to the 
oysters that are put into them, in four or 
five days ; though they commonly let tiiem 
continue there six weeks or two months, in 
which time they will be of a dark green. 
To prove that the sun operates in the 
greening, Tolesbury pits will green only in 
summer ; but that the earth hath the greater 
power, Brickel Sea pits green both winter 
and summer ; and for a further proof, a pit 
within a foot of a greening pit will not 
green ; and those that did green very well, 
will in time lose their qualify. 
The oysters, when the tide comes in, lit 
G 
